Bjorn, as you show so much dedication, let me offer some construtive criticism for the art then. I hope it also gives you a little direction.
First, the stories in the campaigns have very little humor in them - in fact most of them are concerned with very serious topics. But I think that your humorous drawing style still fits pretty well with the whole. Just something to keep in mind.
I like the old picture of Thron so much, because it captures him for me very well: He is a rather young man thrown into a situation (being the leader) that he is not sure he is ready for. He is melancholy and thoughtful (untypical traits for a barbarian, so it fits that he is rather skinny in yours and the old image). Thron is also forced to fight his brothers and he sees the world his father build being destroyed. And he is no fan of war. He is the good guy in our story.
That said, your picture does not fit (my image) of Thron that well - he looks a little older (which is fine I guess, his job will bring white hairs to every skalp), but the tribal tatooes make him very warrior like. Also he looks like he's full of mischief and slightly annoyed. I wouldn't trust him and I can not really identify with him as a player (personal opinion).
Your image looks a lot like I image Kalitath to look - the traitor that attacks Thron in the third mission. He has no text in the campaign yet - so his image is not used yet. But he will be an important person in the atlanteans second mission.
Just my 2c, hope it helps
When you are interested in more backstory or concepts, we can skype at any time.